Incandescent lamp.



. H. DALE.

INCANDESCENT LAMP.

APPL 1cAT|oN FILED 1AN.20. 1915.

Patented Novn 14, 1916.

UNITED STATES PATENT OFFICE.

JOHN' H; DALE, OF NEW YORK, N. Y., .ASSIGNOB'TO DALE I'JIGHLIN'G'v FIXTURE CO., INC.,

' A CORPORATION OF VNEW YORK.

INCANDESCENT LAMP.

Specification of Letters Iatent.

Patented Nov. 14, 1916.

Application led IanuaryZO, 1915. Serial No. 3,197.

cent lamps and resides in the provision of a ventilated lamp bulb.

In the more recent types of lamps of high 'candle power, and especially in nitrogen a filled lamps, after the lamp has remained lighted for a short period of time the intense heat of the filament is transmitted to the gas in the bulb, the bulb itself, and also to the attached shell and socket plug, so that all of these parts soon reach a relatively high temperature, the result of which is a rapid de'V terioration of the filament, due totheheat of l the nitrogen gas which surrounds it, and

lio'

hence a shorteningl of the life of the lamp.

Theintense heating 'of the socket plug and- "shellfis also objectionable, since it will, by

conduction, cause the heating of the socket to whichv it is connected, and will also cause ab'ieaking -down of the 'insulation of the lead wires ,to the socket, resulting in a short circuit, 'or else the heated socket, may come in contact with some inflammable material, and

in eachinstance the dangerfof fire yis imminent.' i

It is, therefore, the purpose of myfinVen-.

tion to provide means lfor cooling the. bulb,

the `gas'"contained' therein and the' socket plug and: shell, and accordingly my 'invention contemplatesthe provision'of aven-A tilating air conduit arranged in-tlievinterior;

offtheise'aled bulb through whicha constant currntof air circulates which is preferably ducte'd'to the'interior -of-the shell and socket 'where it isk permitted to escape through ventilatingopenings in the shell or sock'et These air condiutsare preferably arranged for a portion of their lengthadjacent ythe lamp filament, and in that way a' variation iin the temperaturebf the air is set up within the conduit, which will cause the'airto flow toward the shell and socket lu i In addition to this, my invention contemplates auxiliary ducts, which, without interfering with the sealedcondition of the bulb, pass from thel exterior of the lamp bulb lamp bulb, and a plurality of them Vmay be v provided if desired.

In the accompanying drawings several embodiments of the invention are shown, which are to be construed in a descriptive and not in a limiting sense, as other equally convenient arrangements of the air duct may be provided, and yet come within ,the purview of the invention.

In Figure 1 of the drawings there is `shown the usual form of a nitrogen filled lampy equipped witha ventilating passage in accordance with the principle of my invention. Figs. 2, 3 and 4 show modifications of the arrangement of the Ventilating air conduit. i

The structureiof the incandescent lamp shownin eachl of the figuresof the drawings is similar to that which is at present employed in nitrogen filled lamps, to which my invention is especially adapted. lThe bulb ofthe lampawhichis sealed, comprises a spherical body portion 1, to which is joined a substantially cylindrical neck 2. Projecting downwardly fromthe upper end of the neck is a-glass stem 3 carrying at its lower end a depending glasspedestal 4. Downwardly directed radiating metallic arms 5 are attached to the pedestal and diverge at their lower-ends, being arranged in somewhat semiconical shape. These arms carry at their lower ends a filament 6. The leads for connecting the filament to a source of current are designated 7 and 8, respectively, and pass downwardly through the glass stem 3 in thesusual manner.l `Attached to they uppei-,end of the neck byv a layer of cement` is a cylindrical shell 9. This shell carries the ordinary socket plug 10, which is joined thereto by a layer of cement 11, in the usual manner. One of the leads 7 is soldered to the shell, as at,12, and the other one, 8, is connected with the insulated center co-n- -itact 13 of the socket plug.

socket plug become heated to high temperature. This phenomenon is not so apparent in the ordinary vacuum incandescent lamp, and it is probable that the excess of heat prsent is due to the reater convection and radiation of the heat rom the filament when nitrogen is used in the ,lamp bulb. Some of the heat, however, is conducted by the glass bulb to the shell and socket plug. In order t0 cool the parts of the lamp a main ventilating air conduit 14 isprovided. As shown iii Fig. 1 this conduit consists of a glass tube which, at its lower end, .is sealed and forms a portion of the bulb, and then extends upwardly in the` interior of the .bulb until it reaches a point substantially on a level with the filament, where it is curved in a horizontal plane around the filament, and then extends upwardly along the wall of the neck and, at itsy upper end is again sealed to the glass bulb. ln the construction of the lamp the conduit 14 may be blown integral with the lamp bulb, as shown, o r it may be formed from a separate tube, in which instance it would be placed in position and sealed -before the air was' exhausted from the bulb and the same filled with the nitrogen through the tip 16. The air which circulates freely in the hollow shell and socket plug is permitted to escape from lthe 1nterior of the shell and socket plug through the s aced vent holes 17 in the periphery of the ls ell. In order to maintain the plug and shell at a still lower temperature an auxilia'ry duct or opening 18 may be provided, whichconnects the main duct 14 to the atmosphere at a point above the filament.

When a lamp of the character described remains lighted for a considerable period of time the heat generated by the filament will be transmitted by convection and radiation to the portion of the column of air within the conduit 14 which surrounds the filament. The air within the hollow shell and socket plug will also become heated to a greater extent than the atmospheric air which surrounds the bulb. The variations of temperature of the air within the conduit will therefore cause a current of air to flow through the same `toward the neck of the bulb and to circulate freely within the hollow shell and socket plug, escaping through the vent openings or holes 17. This air,

while it is necessarily heated to some extent in its passage through the conduit 14, nevertheless materially reduces the temperature of the gas within the bulb, and hence the bulb itself, as well as the shell and socket plug,'and in this manner the life of the lamp is increased, since the-filament will not deteriorate as rapidly as where the gas Within the bulb is permitted to reach a much higher temperature. The reduction, of the temperature of the shell and socket plug is also Sulliclent to render the likelihood of fire remote.

naoaaa Aiary duct 18, in which instance the current of air which passes through the main duct 14 will suck in a volume of the colder atmospheric air surrounding the neck of the bulb, which will pass into the interior of the hollow shell and socket plug as before, and will thereby cause a greater reduction of temperature in these parts.

The form of lamp shown inv Fig. 2 may also be utilized, but in this instance the standard form of incandescent lamp must be somewhat changed. The stern 3 of the lamp is hollow and, instead of ii'eing sealed at its lower end, is extended by means of a tube 21 through the spherical portion of the bulb to the periphery of the same, where it is sealed. The stem is provided at its free end with an annular shoulder 23 which forms a support for the radiating arm 5 carrying the filament 6. The other structural features of the lamp are similar to the one already described, 'and in its operation, the air will be caused to flow through the conduit provided yinto the interior of the shell and socket plug and out through the openings therein, as before.

In Fig. 3 a lamp is shown in which a pair of conduits 24 and 25 are provided, which extend from the periphery of the lamp adjacent its tip 16, through the spherical portion -and neck of the lamp, leading into the` chamber formed by the hollow shell and socket plug, which, as before, is provided with Vent openings 17. Auxiliary air ducts 26 may be provided in each of these conduits. When the lamp is lighted the air flows through these conduits in the manner previously described, and since a plurality of them are provided the gas in the bulb,

the bulb, and the shell and socket, will obviously be cooled to a lower temperature, due to the greater volume of air which passes through the conduits.

In Fig. 4 an arrangement of lconduits is shown which is designed to coolonly the gas within the bulb and the bulb itself, and in this instance the air conduits which are designated 27 and 28 pass through only the spherical portion of the lamp bulb, and

The Ventilating tubes may be of any desired cross section, the particular contour lill@ of the cross section being determined by the character and uses to which the lamp is to be put and it is intended that the term tubular as used .in the claims, is sufficiently broad to coveral tube of a regular or irregular shape in cross section.

I claim- 1. The combination, with an incandescent lamp comprising a lamp bulb having a. body portion, a neck and a socket plug attached to said neck, of a tubular member passing through the body and neck of said bulb and opening into a space between the socket plug and neck of the bulb.

2. The combination, with an incandescent lampv comprising a bulb consisting of a body portion and a neck, a filament in said body portion and a hollow socket plug attached to said neck,'-of a tubular member passing through said body portion and neck of said blub and leading into a chamber formed between the hollow socket plug and neck, and means for permitting the escape of air from said chamber.

3. The combination, with an incandescent lamp comprising al lamp bulb consisting of a body portion and neck, a filament in said body portion and a hollow shell and socket plug attached to said neck, of a tubular member' passing through the body of said lamp through the neck of the bulb and lead- -ing into the hollow chamber formed between the hollow shell and socket plug and neck of said bulb, said shell having vent openings therein. v

4. The combination, with an incandescent lamp comprising a lamp bulb consisting of a body portion and neck, a filament in said bodyportion and a hollow shell and ,socket plug attached to said neck, ofVl a tubular' member passing through the body of said lamp and having a portionthereof adjacent said filament, the remainder of said tubular member passing through the neck of the bulb and leading into the hollow chamber formed between the hollow shell and socket plug and neck of said bulb, said shell vand a socket plug attached to said neck, of

al Ventilating air conduit passing through the body and neck of said bulb and opening into a space between the socket plug and neck, and an auxiliary conduit leading from the atmosphere into said main conduit at a point above said filament.

6. The combination, with anl incandescent lamp comprisinga sealed lamp bulb and a hollow base attached thereto, of a ventilating air conduit passing through said bulb and leading into the interior of said base, said base having vent openings therein.

7 The combination, with an incandescent lamp comprising a sealed lamp bulb containing a lightv yielding element and a hollow base attached thereto, of an air ventilating conduit passing through said bulb and leading into the interior of said hollow base,

`and an auxiliary conduit leading from said atmosphere into said main conduit at a point above said light yielding element, and said base having vent openings therein.

' In witness whereof, I subscribe my signature, in the presence of two witnesses.

JOHN H. DALE.

Witnesses: WALDo M. CHAPIN, JOSEPH A. BUGKLEY. 

